Method of prolonging the life of expansible vulcanizing cores



Apr. 17,1923. 4 1,452,326' J. D. TEW

METHOD OF PROLONQTNG THE LIFE OF EXPANSIBLE VULCANIZING CORES Filed July 1, 1922 K 12 Jain ms fl flew.

y/WM en ma A r. 17, iezs. i 1,452,326 .fiJhiTED STATE {EFF-ICE.

James :0. new, or enson, onro, ASSIGNOR TO run 3. r. ooonnrcn comm, or NEW YORK, u. an, a coaroaarron or new roan.

METHOD OF PROLONGING THELIFE F EXPANSIBLEVULCA'NIZII IG Application filed July 1, 1922. Serial No. 572,255.

To all whom it may canoe-m: tions. 12 is the base portion of the bag, Be it l Il0WI1 that I, JAMES D. Tsw, a cltiwhich is of thick-walled construction and zen of the United. States, residingat Hudnot adapted to stretch substantially in the son',.in the county of Summit and State of vulcanizing of the tire and is therefore less Ohio, have invented a certain new and usesubjectto the defects referred to as bein ful Method of Prolonging the Life of EX- present in other parts of the bag. 13 is the pansible Vulcanizing Cores, of which the folstem mounted in the base-portion 12 for conlowing is a specification. ducting pressure fiuid'into the bag.

This invention relates to theart of vul' In practicing my method I remove the de- 10 canizing pneumatic tire casings on expansiteriorated material 11 from the body ofthe ble cores or bags, commonly known as air bag, preferably by abrading or bufiing, as bags or water bags. These bags have usually with a rasp 14 or other suitable tool, exposbeen made either of layers of rubberized fabing the underlying, substantially-unaffected. ric or of a thick wall of soft rubber reinportion 15, to which the sulphur has not 15 forced with fabric at the base. I have obpenetrated in such quantities as to causeovertained better results with the latter type of curing or excessive loss of elasticity. The

bag than the former, one advantage among material is preferably removed to substam others being that owing to its thick but plitially the same depth over the'entire crown ablewall, deterioration can be observed and of the bag, such depth depending u on the the bag taken out of service before it "bursts depth to which the worst ofthe crac s have with the possible result of ruining an entire penetrated, the bag then having the appearheat of tires through vulcanizing them withance shown in Fig. 3, with a more or lessout any internal pressure. rough surface, depending upon the character It is the object of my invention to prolong of the means used'in removing the last of the the life of bags of this class, and especially abraded material. I then apply a sheet of those of the thick-Walled rubber variety, and unvulcanized rubber 16 to the newly exposed to that end I have devised a plan of renewsurface of the bag, preferably, with an ining the outer surface of the bag after it has tervening layer of rubber cement (not shown) become hardened or over-vulcanized-and has where it may be permanently and more firm- 1begun to crack but preferably before the ly secured by subsequent heating and pressmain body of the bag-wall has become submg in use or, preferably, by the application stantially hardened or deeply cracked. This of heat and pressure, by any suitable means, 'may be done by scraping off the hardened as by expanding the bag in a suitable vul crust and substituting a fresh coating of rubcanizing mold, before further use. The bag 35 ber having no sulphur or less than a vulcanmay be repeatedly re-covered from time to izing content of sulphur. I do not broadly time, in this way. and its life greatly pro-- claim a. vulcanizing bag of this construction, longed at comparatively small expenseflhe. but the employment of such a veneer in carnew rubber, l6, shielding the main body of rying out my invention is found to give good the bag from su phur emanating from suc- 40 results. cessive tires. .95.

Of the accompanying drawings: 1 The sheet of new rubber, 16, preferably is Fig. 1 is a side view of a part of a rubber, of a compound containing a small amount, tire-vulcanizing bag which to a degree has but less than the usual vulcanizing percentdeteriorated, as above mentioned. age, of sulphur, so that itmay absorb a sub- Fig. 2 is a perspective view of the bag ilstant-ial quantity of sulphur from successive lustrating one step in my method. tires in the curing operation before becoming Fig. 3 is a side view of a part of the bag over-cured and so requiring to be removed. as it appears at'a later stage. I do not wholly limit my invention, however,

Fig. 4'is a view in section and perspective to the use of such paucity of sulphur, or; to 50 of the bag as it appears after-the application the use of. any sulphur, initially, in said of my method thereto. sheet, nor do I otherwise limit it except as Referring to the drawings, 10 is the body required by'the prior artor as defined in the of the bag and 11 indicates the checked or appended claims. cracked condition of its outer surface result- Theterm rubber as applied in the claims 55 ing from successive tire-vulcanizingoperato the material composing the wall of the sively removing said bag includes, unless otherwise limited, rubberized fabric.

I claim:

1. In the art of vulcanizing pneumatic tire casings on fiuid-expansible, rubber cores, the method which comprises using the core in repeated vulcanizations until a hardened crust has formed on its outer surface, removing said crust, substituting a fresh rubber coating, and using the core in further vulcanizations;

2. In the art of ulcanizing pneumatic tire casings on fluid-expansible, rubber cores, the method which comprises using the core in repeated vulcanizations until a hardened crust has formed on its outer surface, abracrust, substituting a fresh rubber coating, and using the core in further vulcanizations.

3., In the art of vulcanizing pneumatic tire casings on fluid-expansible, rubber cores, the method which comprises using the core in repeated vulcanizations until a hardened crust has formed onits outer Surface, re-

moving said crust, substituting a fresh rubber coating containing less than a normal vulcanizing, percentage of sulphur, and using the core in further vulcanizations.

4. In the art of vulcanizing pneumatic tire casings on fiuid-distensible coreshaving thick walls composed primarily of an underbody of soft vulcanized rubber and a veneer of originally unvulcanized rubber, the method which comprises using said core in repeated vulcanizations until the veneer has become over-vulcanized, removing the hardened veneer, and applying to the core a fresh, unvulcanized rubber veneer.

5. In the art of vulcanizing pneumatic tire casings on fluid expansible, rubber cores, the method which comprises using the core in repeated vulcanizations until a hardened crust has formed on its outer surface, removing' said crust before cracks have deeply penetrated the body of the core, substituting a fresh coating of unvulcanized rubber, and using the core in further vuloanizations.

6. In the art of vulcanizing pneumatic tire casings on fluid-expansible, ru ber cores,

the method which comprises using the corein repeated vulcanizations until a hardened crust has formed on its outer surface, abrasively removing said crust before cracks have deeply penetrated the body of the core, substituting a fresh, unvulcanized rubber coating, and using the core in further vulcanizations.

T. In the art of vulcanizing pneumatic tire casings on fluid-expansible, rubber cores, the method which comprises using the core in repeated vulcanizations until a hardened crust has formed on its outer surface, removing said crust before cracks have deeply penetrated the body of the core, substituting a fresh, unvulcanized rubber coating containing less than a normal vulcanizing percentage of sulphur, and using the core in further vulcanizations.

8. In the art of vulcanizing pneumatic tire casings on fiuid-distensible cores having thick walls composed primarily of an underbody of soft vulcanized rubber and a veneerofi originally unvulcanized rubber, the method which comprises using said core in repeated vulcanizations until the veneer has become over-vulcanized, removing the hardened veneer before cracks have deeply penetrated the rubber under-body, and applying to the core a fresh unvulcauized rubber veneer.

In witness whereof I have hereunto set my hand this 27 day of June, 1922.

JAMES D. TEW. 

